1. Field of the Invention
The present invention relates to a radio apparatus that detects the position of the radio apparatus and transmits the position information to a search requester. The present invention also relates to a position search system and a position search method using such an apparatus.
2. Description of the Related Art
In recent years, various systems have been developed that use a portable telephone capable of determining its own position information. For example, there is a position search system in which, when a portable telephone receives a search request from a third party, the portable telephone determines its position information and transmits the position information to the third party.
FIG. 1 is a flowchart showing the operation of such a portable telephone. In FIG. 1, when the portable telephone (which is the destination of the search request) gets an incoming call (S11), the portable telephone performs an incoming call response regardless of the content of the incoming call (S12). Next, the portable telephone determines whether or not the source of the incoming call will receive the results of the search request sent from the third party, e.g., another portable telephone which is the source of the search request (S13). When the portable telephone determines that the source of the incoming call will not receive the results of the search request, the portable telephone performs a normal incoming call processing (S14). On the other hand, if the portable telephone determines that the incoming call will be receiving the results of the search request, the positioning mechanism provided in the portable telephone judges whether the portable telephone is capable of determining its position information (S15). When the positioning mechanism judges that the portable telephone is incapable of determining its position information, the portable telephone completes the operation without transmitting any position information to the portable telephone that is the source of the search request (S16). On the other hand, when the positioning mechanism judges that the portable telephone is capable of determining its position information, the portable telephone checks received information regarding the portable telephone that is the source of the search request (S17) and performs determines its position information (S18). The position information is then transmitted to the portable telephone that is the source of the search request (S19).
However, in the above-described position detecting system, when the portable telephone receives a search request from a third party when it is incapable of determining its position information, the portable telephone cannot transmit the position information to the third party because the portable telephone cannot determine its position information. Therefore, when the third party does not get a response to the search request, the third party is unaware of the reason, e.g., the portable telephone did not receive the search request sent by the third party, the portable telephone is incapable of determining its position information, the portable telephone rejected the incoming call of the search request, or the portable telephone rejects determining its position information.